What is NOT true about the PRA device on the SCBA apparatus?

The statement that the PRA device on the SCBA apparatus reduces pressure below atmospheric pressure is not true. The purpose of the Pressure Regulating Assembly (PRA) is to manage and distribute airflow, ensuring that it provides consistent and safe pressure to the user’s facepiece during operation.

The PRA device is designed to maintain a pressure that is above atmospheric levels, allowing for a proper seal and suitable breathing conditions for the firefighter. It does not function to lower the pressure to sub-atmospheric levels, as that would be counterproductive to the safety and effectiveness of the breathing apparatus.

The other features of the PRA device, such as providing real-time pressure readings and alerting users to low pressure, highlight its essential role in the safe and effective use of SCBA equipment. Boosting facepiece pressure is also a critical function to ensure that the mask seal remains intact under varying conditions. Therefore, the role of the PRA in maintaining a positive pressure ensures that it operates effectively for the safety of the user.